Tracked walking gear

ABSTRACT

For a machine, for example a power loader, coal cutter or drilling rig running on a track in a mine, the machine including a ram attached thereto, walking gear connected to said ram and mounted to be slidable on the track or on a rail extending parallel to the track, the gear having two effective positions determined by initial actuation of the ram, in one position the gear being locked to the rail whereby further movement of the ram moves the machine along its tracks away from the stationary gear, and in the other position the gear being freely slidable along its rail whereby movement of the ram draws the gear towards the stationary machine.

Bolton [111 3,871,277 1451 Mar. 18,1975

1 1 TRACKED WALKING GEAR [76] lnventori Robert Benjamin Bolton, 14 Middle Dr., Northumberland, England 221 Filed: Feb. 25, 1974 21 Appl. No.: 445,477

[52] US. Cl. 105/31, 104/147 R, 104/165,

173/141, 254/106 [51] Int. Cl. B61c 13/00 [58] Field of Search 104/147 R, 165; 105/30,

3,682,261 8/1972 Bird 175/122 Primary Examiner-Lloyd L. King 1 Assistant ExaminerRandolph A. Reese Attorney, Agent, or FirmLarson, Taylor and Hinds [57] ABSTRACT For a machine, for example a power loader, coal cutter or drilling rig running on a track in a mine, the machine including a ram attached thereto, walking gear connected to said ram and mounted to be slidable on the track or on a rail extending parallel to the track, the gear having two effective positions determined by initial actuation of the ram, in one position the gear being locked to the rail whereby further movement of the ram moves the machine along its tracks away from the stationary gear, and in the other position the gear being freely slidable along its rail whereby movement of the ram draws the gear towards the stationary machine.

PATENTH] MAR I 8 I975 sum 1 or 4 SHEEI 2 BF 4 PATENTED HAR I 8|975 SHEEI 3 UF 4 TRACKED WALKING GEAR The present invention relates to tracked walking gear such as is used in machines which have to drive themselves along a track during operation or in order to position themselves for operation.

There are known power loaders or coal cutters that are moved across a face by means of a motor and gear that engages a tensioned chain extending across the coal face. The cutting action is dependent on the force that the cutter manages to exert on the coal face by means of its gear that engages the chain. The chain therefore needs to be of high quality and is necessarily very heavy. Large chain tensioning devices are needed to provide the chain with constant tension. The chain and particularly its tensioning devices are a major source of expense. Also only one cutter can operate on the coal face at any one time since the strength of chain required to allow two cutters to operate would be prohibitively expensive andcumbersome to produce.

Further, there are known drill rigs, used for example in preparing coal faces in mines for blasting, in which the rigs run on rails leading up to a coat face. Often blasting is carried out as a series of explosions, and between each one the rig has to be run up to the face and run back again to a safe distance. The length of rail over which the rig runs is usually several times the length of the stroke of the hydraulic rams used to move the rig. The ends of the ram pistons remote from the rig are anchored to the rails by means of bolts to give a secure base against which the rams can push to move the rig and to hold the rig in position during drilling. The anchoring bolts for the ram pistons have to be moved several times during a run up to the coal face. This is time-consuming and it is also expensive in that the rails need to be provided with holes to accommodate the anchoring bolts.

According to the present invention there is provided, for a machine to be driven along one or more tracks or rails, said machine including a reciprocable drive rod, walking gear including a holding mechanism comprising a trapping member for slidably engaging a rail or track, a jamming member pivotally mounted on the trapping member, and means adapted to connect the drive rod to the jamming member in such a way that, in use, movement of the drive rod in one direction pivots the jamming member from a rest position in which it is out of pressurised contact with the rail or track into an operative position forcing it onto the rail or track, whereby the rail or track is gripped between a trapping surface of the trapping member and the jamming member, the holding mechanism thereby being located in position relative to the rail or track, subsequent movement of the drive rod in the other direction pivoting the jamming member back towards its rest position to release said member from the rail or track so that the holding mechanism is free to slide along said rail or track.

Thus it will be appreciated that such gear can be mounted on a power loader or coal cutter to co-operate with an associated rail and provide a continuous or nearly continuous drive to said loader or cutter, thus simplifying movement of the loader or cutter along a coal face, eliminating said expensive chains and tensioning devices and restricting undesirable lateral movement of the cutter. Further, a drilling rig incorporating such walking gear can readily be moved towards and away from a coal face without the laborious procedure involving removal and re-insertion of bolts as mentioned above.

Preferably the means adapted to connect the drive rod to the jamming member includes a shuttle member slidably mounted in, to be movable relative to, a receiving portion of the holding mechanism, a pin dependent from the shuttle member co-operating with the jamming member in such a manner that, in use, movement of the drive rod in the one direction results in movement of said pin in the one direction and, consequently, said pivoting movement of the jamming member. Conveniently the pin engages with the jamming member at a position to the side of the pivotal mounting of said member on the trapping member remote from the rail or track.

In a preferred embodiment of the invention the jamming member is double acting in the sense that it can pivot in either direction from its rest position to lock the holding mechanism to the rail or track, the walking gear further including adjustable stop means with positions to limit clockwise or anticlockwise movement respectively of the jamming member. These positions of the stop means may be mutually exclusive, the arrangement being such that movement of the shuttle member to rotate the jamming member in a clockwise direction from the rest position is permitted while the reverse movement is prevented, or, alternatively, movement of the shuttle member to rotate'the jamming member in an anticlockwise direction from the rest position is permitted while the reverse movement is prevented. In this way the holding mechanism can be used for forward or reverse travel of the machine.

An embodiment of the present invention will now be described, by way of example only, with reference to the accompanying drawings of which:

FIG. 1 is a side view of walking gear according to the invention;

FIG. 2 is a plan 'view from below of the gear of FIG. 1;

FIG. 3 is an end view of the gear of FIG. 1, and FIG. 4 is a vertical section on the line IV-IV of FIG.

Referring to the drawings, the holding mechanism,

- indicated generally at 2, is arranged to operate on the vertical flange 4 of a substantially inverted T-section rail 6. The mechanism 2 comprises a pair of opposed side pieces 8, 10. The inner, vertical face of the side piece 8 lies adjacent one side face of the flange 4 of the rail 6, a pair of plates 12, 14 being resiliently urged, by means of springs 16, 18 housed within the piece 8, into contact with said side face of the flange 4. Thus the holding mechanism is biased so that the side piece 10 thereof is urged towards its associated side face of the flange 4 of the rail 6.

Integrally formed with the side pieces 8, 10 of the holding mechanism is a cylindrical receiving portion 20, one side wall of which is slotted at 22.

Slidably mounted in the receiving portion 20 of the holding mechanism is a cylindrical shuttle 24 the length of which is greater than that of the portion 20 as can be seen in FIGS. 1 and 2, a pair of increased-diameter flanges 26, 28 being formed on the ends of said shuttle 24.

Each end face of the cylindrical shuttle 24 is bored to receive therein a piston, such as 30, of a ram mounted on a machine (not shown), for example a power loader, coal cutter or drilling rig, the piston being secured to the shuttle by a pin extending through both the shuttle and the piston.

Projecting through the slot 22 in the receiving portion 20 of the holding mechanism 2 is a connecting piece 32 rigidly secured to, to be movable with, the shuttle 24. Said piece 32 includes a vertical portion 34 from the lower surface of which depends a cylindrical, vertical pin 36, the pin being received within an elongate, horizontal slot 38 formed in a base plate 40 forming part of the side piece of the holding mechanism.

Thus it will be appreciated that the arrangement so far described is such that reciprocation of the piston 30 will result in corresponding sliding movement of the shuttle 24 and associated components relative to the holding mechanism, and, more particularly, longitudinal movement of the pin 36 in its slot 38. The limit of movement of the shuttle 24 relative to the housing mechanism 2 is determined by, at this stage, abutment of the connecting piece 32 with the ends of the slot 22.

The walking gear further includes a jamming member 42 lying in a horizontal plane and extending through, to be supported in, a slot formed in the side piece 10 of the holding mechanism, the rear of said member 42 resting on the base plate 40 of said mechanism as best seen in FIG. 4. The member 42 is pivotally mounted, at a region adjacent the rail 6, on a vertical pivot screw 44 screwed up into the side piece 10 of the holding mechanism, again as best seen in FIG. 4, said member 42 thereby being pivotable in a horizontal plane about said screw 44.

The jamming member 42 includes a slot 46 elongated in a direction perpendicular to the length of the rail 6, through which slot extends the vertical pin 36. The arrangement of slot 46 and pin 36 is such that, on said linear reciprocating movement of the pin 36 which results from reciprocation of the piston 30, said pin 36 effects pivoting movement of the member 42 about its pivot 44, the slot 46 being shaped to accommodate the resulting arcuate displacement of the jamming member 42 about its pivot screw 44.

The operative surface 48 of the member 42 is of arcuate, serrated form as seen in FIG. 2, the member 42 having the rest position shown in FIG. 2 in which the point of minimum radius from the screw 44 lies adjacent to the associated side face of the flange 4 of the rail 6. The radius of said surface 48'about the pivot screw 44 increases in both a clockwise and an anticlockwise direction from said point of minimum radius. Thus, on said pivoting movement of the jamming member 42, an increased-diameter portion of the serrated surface 48 is moved into pressurized contact with the rail 6, said rail being jammed between said surface of the jamming member 42 and the trapping surface of the side piece 8 said trapping surface in fact comprises a pair of spaced studs 50 having serrated surfaces projecting slightly forwardly from the inner surface of the side piece 8 as best seen in FIG. 2.

Stop means are provided to limit the pivoting movement of the jamming member 42 in either direction as desired. Said means comprise a pair of arcuate rods 52, 53 having handles 54, 55 and including horizontal bars 60, 62, extending through, to be rotatable in, bushes 64, 66 welded to the receiving portion 20. The rod 52 can be located between the flange 26 of the shuttle 24 and the adjacent end face of the portion 20 to prevent movement of the shuttle member from left to right, as seen in FIG. 1, relative to the holding mechanism and thus prevent resultant anticlockwise movement of the member 42. The rod 53 can similarly be located between the flange 28 and the other end face of the portion to prevent movement of the shuttle 24 from right to left, as seen in FIG. 1, and therefore prevent resultant clockwise movement of the member 42. Compression springs 56, 58 reacting between faces 68, 70 of the bushes 64, 66 and pins 72, 74 at the ends of the bars 60, 62 urge the rods 52, 53 to rest positions inwardly of their operative positions, the rest positions being shown in FIG. 1. A rod 52, 53 can thus be inserted into its operative position by withdrawing the bars 60 or 62 thereby further comprising the associated spring 56 or 58 against its associated face 68, and pivoting the rod to its operative position between its flange 26 or 28 and the portion 20. The spring then helps maintain the rod in its operative position.

In operation, when a machine (not shown) attached to the holding mechanism 2 by means of the piston 30 of a ram (not shown) is to travel in the direction of arrow X in FIG. 1, the piston 30 is extended thus producing a clockwise moment on the jamming member 42. The serrated surface 48 of said member then presses against the side of the flange 4 of the rail 6 to jam said flange 4 between the member 42 and the studs 50. The holding mechanism 2 is thus tightly clamped to the rail 6 so that further extension of the piston 30 causes the attached machine to move in the direction of arrow X. Due to the increase in radius of the surface 48 about the pivot screw 44, the greater the force exerted by the piston 30 along its length the greater is the clamping force on the mechanism 2.

The stop rod 52 is located between the flange 26 and the associated end face of the portion 20, and when the machine has moved a length corresponding to the stroke of the'piston 30, the latter is contracted and this produces an anticlockwise moment on the jamming member 42, which returns said member toward its rest position and relieves thepressure on the flange 4. The presence of the stop rod 52 between the flange 26 and portion 20 prevents further anticlockwise pivoting movement of the jamming member beyond its rest position shown in FIG. 2, so that further contraction of the piston 30 pulls the holding mechanism 2, which is now free to slide along the rail 6, in the direction X towards the machine.

Movement in the reverse direction of a machine attachedto the holding mechanism 2 can be obtained by operating the piston 30 sufficiently to enable the rod 52 to be pivoted from its operative position and then locating rod 53 in its operative position.

The fact that the jamming member 42 engages with the side of a rail, as opposed to the top surface of a rail, has distinct advantages, particularly in dirty conditions such as exist in mines where dirt can settle on top of rails. It will be noted that the lower end regions of each side piece 8, 10 are shaped to direct any dirt and dust away from the walking gear. It is preferred that said gear be operable on a rail raised above the floor of the mine thereby reducing the possibility of dust and dirt affecting the operation thereof. Further, the relative heights of abutting lengths of rail such as 6 sometimes vary, and it will be appreciated that a jamming member operating on the side of such lengths will not be affected by such variations in height.

As can be seen in FIG. 4, the serrations of the surface 48 of the member 42 are slightly V-shaped in vertical section, thus giving substantially point contact of each tooth with the rail 6, improving frictional contact therewith and reducing the possibility of deformation of the rail.

In the application of the invention to a power loader or coal cutter running along a track extending across the coal face, a rail of circular cross-section iswelded along the length of the track to be positioned above said track and to leave the major cross-section of the rail free for engagement by a claw member integral with the cutter and which co-operates with the rail to restrict lateral movement of the cutter on its tracks. The cutter has a cutting member mounted on the side of the cutter remote from the rail, and a substantially constant thickness of coal seam can be engaged by the cutting member.

Hydraulic rams are secured one to each end of the underside of the carriage portion of the coal cutter, the pistons of said rams being secured to associated holding mechanisms as detailed above, which mechanisms are themselves adapted for mounting on the rail. The arrangement of rams is preferably such as to be capable to give a continuous or nearly continuous driving force urging the coal cutter along its associated track, one ram performing its driving stroke whilst the other one is moving its associated holding mechanism into position for the driving stroke.

It may be that a rail of different cross-section would be needed in different circumstances, and a particularly suitable cross-sectional form might comprise a square being mounted on the track by one of the corners of its cross-section so as to give two corners which can be engaged by the adapted holding mechanism.

As mentioned above, walking gear according to the invention can, amongst other applications, be used on drilling rigs which have to be moved frequently towards and away from a coal face to be prepared for blasting.

What I claim and desire to protect by Letters Patent 1. For a machine to be driven along a track or rail having a pair of opposed side faces, said machine including a reciprocable drive rod, walking gear comprising a holding mechanism including a trapping member for slidably engaging a rail or track, a jamming member pivotally mounted on the trapping member, a receiving portion and, slidably mounted in, to be movable relative to, said receiving portion, a shuttle member adapted to be connected to the drive rod of the machine, a pin member being dependent from said shuttle member and co-operating with the jamming member in such a manner that, in use, movement of the drive rod in one direction results in movement ofsaid pin in one direction to pivot the jamming member from its rest position in which it is out of pressurized contact with the rail or track into an operative position forcing it onto the rail or track, whereby the rail or track is gripped between a trapping surface of the trapping member and the jamming member, the holding mechanism thereby being locked in position relative to said rail or track, subsequent movement of the drive rod in the other direction resulting in movement of said pin in the other direction to pivot the jamming member back towards its rest position to release said member from the rail or track so that the holding mechanism is free to slide along said rail or track.

2. Walking gear as claimed in claim 1 in which said pin engages with the jamming member at a position to the side of the pivotal mounting of the jamming member on the trapping member remote from the rail or track when the gear is on the rail or track.

3. Walking gear as claimed in claim 2 in which the jamming member can pivot in either of a clockwise and an anticlockwise direction from its rest position to lock the holding mechanism to the rail or track, the walking gear further including adjustable stop means with positions to limit respectively said clockwise and anticlockwise pivotal movement of the jamming member.

4. Walking gear as claimed in claim 3 in which the adjustable stop means react between the shuttle member and the receiving portion of the holding mechanism, the arrangement being such that movement of the shuttle member relative to the holding mechanism tending to rotate the jamming member in any one of said directions from its rest position can be prevented.

5. Walking gear as claimed in claim 1 in which the jamming member includes an arcuate cam surface adapted to engage with one of said side faces of the rail or track.

6. Walking gear as claimed in claim 5 in which a plurality of serrations are formed on said cam surface.

7. Walking gear as claimed in claim 6 in which the trapping surface is adapted to lie adjacent the other of said side faces of said rail or track, the trapping memone side face of the rail. 

1. For a machine to be driven along a track or rail having a pair of opposed side faces, said machine including a reciprocable drive rod, walking gear comprising a holding mechanism including a trapping member for slidably engaging a rail or track, a jamming member pivotally mounted on the trapping member, a receiving portion and, slidably mounted in, to be movable relative to, said receiving portion, a shuttle member adapted to be connected to the drive rod of the machine, a pin member being dependent from said shuttle member and co-operating with the jamming member in such a manner that, in use, movement of the drive rod in one direction results in movement of said pin in one direction to pivot the jamming member from its rest position in which it is out of pressurized contact with the rail or track into an operative position forcing it onto the rail or track, whereby the rail or track is gripped between a trapping surface of the trapping member and the jamming member, the holding mechanism thereby being locked in position relative to said rail or track, subsequent movement of the drive rod in the other direction resulting in movement of said pin in the other direction to pivot the jamming member back towards its rest position to release said member from the rail or track so that the holding mechanism is free to slide along said rail or track.
 2. Walking gear as claimed in claim 1 in which said pin engages with the jamming member at a position to the side of the pivotal mounting of the jamming member on the trapping member remote from the rail or track when the gear is on the rail or track.
 3. Walking gear as claimed in claim 2 in which the jamming member can pivot in either of a clockwise and an anticlockwise direction from its rest position to lock the holding mechanism to the rail or track, the walking gear further including adjustable stop means with positions to limit respectively said clockwise and anticlockwise pivotal movement of the jamming member.
 4. Walking gear as claimed in claim 3 in which the adjustable stop means react between the shuttle member and the receiving portion of the holding mechanism, the arrangement being such that movement of the shuttle member relative to the holding mechanism tending to rotate the jamming member in any one of said directions from its rest position can be prevented.
 5. Walking gear as claimed in claim 1 in which the jamming member includes an arcuate cam surface adapted to engage with one of said side faces of the rail or track.
 6. Walking gear as claimed in claim 5 in which a plurality of serrations are formed on said cam surface.
 7. Walking gear as claimed in claim 6 in which the trapping surface is adapted to lie adjacent the other of said side faces of said rail or track, the trapping member including resilient means projecting from said trapping surface and adapted to react between the trapping member and the other side face of the rail or track to bias the trapping member towards a position in which the serrations of the jamming member engage with the one side face of the rail. 